Relationships between evaluations of Canadian and USA Holstein bulls for longevity and somatic cell score.

Abstract Canadian and United States evaluations of Holstein bulls were compared for longevity and somatic cell score. A total of 13 236 bulls was evaluated for longevity with 462 bulls having evaluations in both countries, and 10 945 bulls evaluated for somatic cell score with 564 bulls having evaluations in both countries. Multiple across country evaluation procedures were used to estimate the genetic correlations between countries, and to evaluate all bulls on each country's scale of expression. The genetic correlation for longevity (calculated and expressed differently in each country) was 0.91, and for somatic cell score was 0.93, which were as high as correlation estimates for production traits between many countries. The correlation between the international evaluation and the original Canadian evaluations were 0.971 for functional herdlife and 0.981 for somatic cell score, and for the United States were 0.999 and 0.997, respectively. International comparisons of bulls for traits other than production and conformation are feasible

El músculo liso vascular de las grandes arterias: ¿sitio de control local de la función de amortiguamiento arterial?

Introducción y objetivos. Determinar la viscosidad y elasticidad de las arterias aorta y pulmonar y el efecto de la activación del músculo liso vascular sobre la capacidad de amortiguamiento arterial. Material y método. En 6 ovejas anestesiadas se midieron la presión y el diámetro aórtico y pulmonar, en condiciones basales y de hipertensión: a) pasiva, mediante la oclusión mecánica vascular, y b) activa, mediante fenilefrina intravenosa. Se calcularon la elasticidad y viscosidad parietal y se caracterizó la capacidad de amortiguamiento: a) la parietal, mediante el cociente viscosidad/elasticidad, y b) la global de cada circuito mediante la constante de tiempo de descenso de la presión arterial diastólica. Resultados. La viscoelasticidad aórtica fue mayor que la pulmonar (p < 0,05), mientras que ambas arterias tuvieron un amortiguamiento parietal similar. El circuito sistémico presentó un mayor amortiguamiento global (p < 0,05). Durante la hipertensión pasiva se produjo un aumento significativo de la elasticidad sin cambios en la viscosidad, lo que determinó una reducción significativa del amortiguamiento parietal, mientras que el amortiguamiento global de cada circuito disminuyó significativamente. En la hipertensión activa aumentó la viscosidad (p < 0,05), mientras que el amortiguamiento parietal y global recuperaron los valores basales. Conclusiones. La aorta presentó mayor viscoelasticidad que la arteria pulmonar, con un amortiguamiento parietal similar. El amortiguamiento global sistémico fue mayor que el pulmonar. Mientras que la elasticidad depende de la presión intravascular, la viscosidad es un marcador de la activación muscular. La activación muscular resultaría beneficiosa para el sistema cardiovascular, al mantener las funciones de amortiguamiento parietal y global

N-terminal-pro-B type natriuretic peptide as a useful tool to evaluate pulmonary hypertension and cardiac function in CDH infants

Objective: In congenital diaphragmatic hernia (CDH) the severity of pulmonary hypertension (PH) is considered, by several authors, determinant of clinical outcome. Plasmatic N-terminal-pro-B type natriuretic peptide (NT-proBNP) might be useful in diagnosis and management of PH in newborns, although its interest in CDH infants remains to be defined. Early NT-proBNP levels were assessed in CDH infants and correlated with cardiovascular echocardiographic parameters. Patients and Methods: 28 newborns, CDH and age-matched controls were enrolled in a prospective study. Clinical condition, NT-proBNP plasmatic levels, echo parameters of PH and biventricular function were assessed at 24 h after delivery as well as survival outcome. Results: Estimated mean pulmonary pressure and NT-proBNP were significantly higher in CDH than control infants. NT-proBNP significantly correlated with estimated pulmonary artery pressure, right ventricular Tei index, and tricuspid E/A ratio. Additionally, we found that CDH infants with NT-proBNP >11,500 pg/ml experienced a worse prognosis. Conclusions: We demonstrated that PH is associated with NT-proBNP elevation and diastolic impairment in CDH infants. Early elevations in NT-proBNP levels seem to alert for a subset of CDH infants with worse prognosis.This study was funded by Fundação para a Ciência e Tecnologia (FCT) through the research project SAU-OBS/56428/200